1. Field of the Invention
This invention relates to a particle analyzing apparatus in a flow sightmeter or the like in which simple adjustment of the positions of a photometering optical system and a flow cell relative to an irradiating optical system is possible.
2. Related Background Art
In a conventional particle analyzing apparatus used in a flow sightmeter or the like, as shown in FIG. 1 of the accompanying drawings, a parallel laser beam L from a laser light source, not shown, is applied to a particle S to be examined flowing at a high speed through the central circulation (or flowing) portion 2 of a flow cell 1 having a minute cross-section of 200 .mu.m.times.200 .mu.m, for instance, while being wrapped in sheath liquid, through the intermediary of a condensing lens 3, as shown in FIG. 2 of the accompanying drawings. Forward scattered light scattered by the particle S to be examined is condensed on a photoelectric detector 5 through an objective 4, whereby information chiefly about the size of the particle S to be examined is obtained. Also, the sidewise scattered light and fluorescence scattered light from the particle S to be examined are condensed on a photoelectric detector 7 through an objective 6, whereby important information chiefly about the complexity of the interior of the particle S to be examined can be obtained.
To accomplish accurate measurement in a flow sightmeter, the optical axis of the laser beam L must be coincident with the center of the flow cell 1 and the scattered lights from the particle S to be examined must be accurately condensed by the photometering objectives 4 and 6. For this purpose, the axis of the flow of the particle S to be examined and the condensing lenses 4 and 6 must be accurately adjusted relative to the optical axis of the laser beam L, but in the conventional apparatus, the flow cell 1 and the photometering optical system are separate from each other and, when the axis of the flow of the particle S to be examined is adjusted relative to the optical axis of the laser beam L in a state in which the flow cell 1 has been finely moved, the position of the optical system for sidewise scattered light deviates and therefore, it is also necessary to adjust the optical system for sidewise scattered light and thus, operation becomes cumbersome and moreover, it is difficult to effect sufficiently accurate adjustment.